3 Aug 2015 23:05

Roscosmos may launch 6 Proton launch vehicles with communications satellites on board in Aug-Nov 2015 - source

MOSCOW. Aug 3 (Interfax-AVN) - The Russian Federal Space Agency Roscosmos plans to carry out six launches of a Proton-M launch vehicle within the next four months, one of them for the Defense Ministry, a Russian space rocket industry source told Interfax-AVN on Monday.

"Roscosmos has already announced a Proton-M launch carrying the British communications satellite Inmarsat 5 F3, scheduled for August 28. In addition, the launch of a Proton-M carrying an Express-AM8 communications satellite is planned for September 14, and the Turkish spacecraft Turksat 4B is to be put into orbit on October 6. In addition, another launch in the Defense Ministry's interests will take place in October," the source said.

Roscosmos plans also to launch two Proton vehicles in November to put the Eutelsat 9B and Express-AMU-1 telecommunications satellites into orbit, he said.

The Proton launches were suspended following the crash of such a vehicle carrying a Mexican telecommunications satellite in May 2015.

The Khrunichev space research and production center had reported earlier that the launches of Proton rockets would be resumed following the May crash on August 28 by sending the British telecommunications satellite Inmarsat 5 F3 into space.

Proton missions were suspended following the failed launch of a Mexican communications satellite in May 2015. A Proton-M rocket with a Briz-M upper stage and the MexSat-1 Mexican communication satellite onboard blasted off from Baikonur on May 16. The engine of the rocket's upper stage shut down during the 498th second of the flight, reportedly above the Transbaikal territory at an altitude of about 161 kilometers, one minute before the payload was to separate from the launch vehicle. "The third stage, the upper stage, and the spacecraft burned up in the atmosphere," Roscosmos said.

A government commission investigating the crash concluded that the failed Proton-M mission was due to the failure of the 3rd stage's thruster because of increased vibration caused by the misbalance of the turbo-pump unit's rotor, whose performance was affected by high temperatures and an imperfect balance system. The commission also said in its conclusions that the crash was caused by the design factor.